This is a companion post to the OOMA DNS configuration post. If you don’t want to know what’s going on under the covers then you can just skip reading now.
DNS Request Flow
Domain Name Servers (DNS) translate the familiar web names to computer understandable numbers. Every single internet connected machine is assigned a unique number. You could type in http://72.14.204.99 in your browser and get to Google or you could type in http://google.com – clearly google.com is going to be easier to remember than the number (IP address). Even if you were to remember Google’s IP address what about all of the other web sites that you go to – how would you remember all of their IP addresses? Clearly (for people) a name based system (DNS) makes sense.
Computers however still work on a numbering system so every time you type in a name the computer sends the name to a DNS server for translation. The DNS servers get called at least once (and frequently dozens of times depending on the type of resource being requested). Unless you are on a pure text-only web page then every image, script, icon, button and link on a web page has its own name and so a single request for a web page could result in several DNS requests. Read the rest of this entry »